Improvement in safety-valves



J. G. SCHAEFER. Safety-Valves.

Ne. 212,576. Patented Feb. 25,1879.

N. PETERS, PHDTO-LgTMcGRAPHEm WASHINGTON, Dv C UNITED Srarns PATENTOmron.

JOHN O. SOHAEFER, OF NEW YORK, N. Y.

4 IMPROVEMENT IN SAFETY-VALVES.

Specification forming part of Letters Patent No. 212,576, dated February25, 187 9 application filed December 4, 1878.

.To all whom it may concern:

Be it known that I, J onN (J. SOHAEFER, of the city, county, and Stateof New York, have invented a new and useful Improvement inSafety-Valves, which improvement is fully set forth in the followingspecification, reference being had to the accompanying drawing, whichrepresents a longitudinal vertical section.

This invention consists in the combination, with a discharge-pipe, of anelastic ball or diaphragm arranged to actuate a lever which is connectedwith a blow-off valve, said lever being provided with a stem restingupon said diaphragm, and depressed by a weight, which has a tendency tokeep the blow-oif valve closed, so that the position of said blow-oft'valve is regulated by the pressure acting on the elastic ball ordiaphragm, and that when the blowoff valve is forced down a slightdiminution in the pressure allows the same to close. The discharge-pipepermits an exhaust independently of the blow-oft' valve.

Safety-valves are usually constructed with conical faces iittin gcorresponding1 conical seats; and if such a valve is closed, its innersmallest surface is exposed to the action of the pressure produced bysteam, compressed air, or other liquids or iiuids under pressure. lf avalve of this class is adjusted so that it will be raised when thepressure reaches a certain point, the steam or other fluid flows offwhenever the pressure exceeds this point, but as soon as the valve hasbeen raised from its seat the surface ot the valve which becomes exposedto the pressure of the steam or other fluid is increased, and the valvedoes not return to its seat until the pressure is reduced considerablybelow the point to which the valve has been adjustedthat is to say, ifthe valve has been set to, say, seventy pounds, it will commence to blowOif as soon as the pressure rises to a little above seventy pounds; butafter the valve has been raised from its seat it will continue to blowoft' until the pressure has been reduced to sixty-tive pounds, or evenless, according to the diameter ofthe valve. This diflicultyis wellknown but in safetyvalvcs for steam-boilers it is of little consequence.But if a safety-valve is to be used for very low pressures-for instance,in ripening casks for lager-beer, where the pres ence of carbonio acidgenerated in said cashs does not exceed four pounds to the squareinch-it becomes ofthe greatest importance that the valve shall blow Offexactly at thepoint desired, and that it shall close down upon its seatimmediately when the pressure has been reduced a little below saidpoint. This Object I have attained by my safety-valve, which is intendedmore particularly for ripening casks, but which may also be used forother purposes. i

In the drawing, the letter A designates a chamber which connects by apipe, B, with the cask or other vessel in which a uniform pressure is tobe maintained. From the pipe B extends a branch pipe, C, to whichissecured a safetya-ralve, D. This safety-valve consists of a shell, a,which is divided by a partition, b, in two compartments, one of whichcommunicates with the branch pipe G, and the other with the blow-offpipe E.

In the partition b is an opening, c, which is closed by the valve d,andthe valvestem e straddles a lever, F, which extends through thechamber A, and on which is secured an adjustable weight, G, which is setto hold the valve d down upon its seat.

The lever F has its fulcrum at a point, j', in

the side of the chamber A, and it extends through the stein g, having ahead, h, that Y rests upon an elastic ball or diaphragm, 2'-, secured inthe bottom part of the chamber A, which special arrangement is notparticularly or specifically claimed herein; nor do I claim anythingshown in the patent of A. De Beau mont, dated April 6, 187 5. A smallchannel, j, permits the gas or other fluid contained in the cash orother vessel to act on the elastic ball or diaphragm i. The weight G isso ad justed that it firmly depresses the valve d upon its scat, andthat the elastic ball or diaphragm is slightly depressed by the head L.If the pressure in the cash or other vessels rises, the elastic ball ordiaphragm causes the stem g to rise, and the valve d, being relieved ofIthe pressure of the weight G, blows off; but as soon as the pressure inthe cash recedes the elastic ball or diaphragm is again compressed, andthe valve d is returned to its seat by the action of the weight G.

It will be seen from this description that the time when the Valve dblows off or returns to its seat depends upon the action of the gas uponthe elastic ball or diaphragmz' and since the exposed area 0f this ballor diaphragm remains uniform at any pressure, and, furthermore, sucharea is much larger than the area ofthe Valve d, the Weight G can bereadily so adj usted that the valve d blows oit' as soon as the pressurereaches the required point, and that when the pressure recedes the valved will be immediately closed by the action of said Weight, the positionof which is controlled by the elastic ball or diaphragm.

For the purpose of discharging` the casks, to which my safety-valve isapplied, I provide a second branch pipe, H, which can be connected to anair-forcin g apparatus.

What I claim as new, and desire to secure by Letters Patent, is-

The combination of the chamber A, having a ball or diaphragm and apipe-extension, a plunger arranged within said chamber and connected toa weighted lever, a safety-valve, also connected to said lever andapplied to an opening in the pipe C, which is a branch of thepipe-extension of chamber A, and the pipe H, branching also from saidextension, and provided with a suitable cock, substantially as and forthe purpose set forth.

In testimony that I claim the foregoing I have hereunto set my hand andseal this 29th l day of November, 1878.

JOHN C. SCHAEFER. [L.s.]

Witnesses:

W. HAUFF, E. F. KAsTENHUBER.

